1. Field of the Invention
The present invention relates to an analyzer, and more particularly, it relates to an analyzer comprising a light irradiation device switching optical filters arranged on a path of light from a light source and irradiating an analyzing object with lights transmitted through the optical filters.
2. Description of the Background Art
In general, an analyzer comprising a light irradiation device switching optical filters arranged on a path of light from a light source in accordance with characteristics of reagents employed for analyses and methods of analyses and irradiating an analyzing object with light having prescribed wavelength characteristics is known as an optical analyzer employed for biochemical tests, blood coagulation tests or the like (Japanese Patent Laying-Open No. 2003-83884, for example). The conventional analyzer disclosed in the aforementioned Japanese Patent Laying-Open No. 2003-83884 is so formed as to switch the wavelength characteristics of the light applied to the analyzing object through the optical filters from the light source by rotating a rotating plate on which a plurality of the optical filters having different light transmission characteristics respectively are set and switching the optical filters arranged on the path of the light from the light source. In the analyzer disclosed in the aforementioned Japanese Patent Laying-Open No. 2003-83884, when the analyzing object is analyzed by irradiating the analyzing object with the light, the analyzing object is analyzed by stopping the optical filter having desired light transmission characteristics at the path of the light from the light source and irradiating the analyzing object with the light having prescribed wavelength characteristics transmitting through the optical filter.
In the conventional analyzer disclosed in aforementioned Japanese Patent Laying-Open No. 2003-83884, however, when the analyzing object is analyzed by irradiating the analyzing object with the light, the optical filter is stopped on the path of the light from the light source and thereafter the analyzing object is irradiated with the light transmitting through the optical filter. In other words, the analysis of the analyzing object is merely performed with the light having specific wavelength characteristics at a prescribed time (temporal point). In some analyses, an optical analysis must be performed continuously or frequently at short intervals not only at the prescribed time. In an analysis of blood coagulation time, for example, light must be applied continuously or intermittently at short intervals of one second or less. Another analysis must be performed by applying a plurality of types of lights having specific wavelength characteristics. In this case, if analyzing a reacted sample, light having first specific wavelength characteristics and light having second specific wavelength characteristics are desired to be applied substantially at the same time.
In the conventional analyzer, however, the rotating plate must be repeatedly rotated and stopped and hence the optical filters are disadvantageously difficult to be switched frequently in a short period. When the optical filters are switched, the rotating plate must be repeatedly rotated and stopped, which disadvantageously complicates control of the rotating plate. The optical filter must be correctly stopped on the path of the light from the light source, and hence an expensive motor having a high positioning accuracy must be employed and positioning of the optical filter with respect to the path of the light from the light source is required.